1. Field of the Invention
The present invention relates to a package structure of optical transceiver component. In particular, the present invention relates to a package structure of optical transceiver component facilitating impedance matching and reducing the simultaneously switching noise.
2. Description of the Related Art
Optical transceivers have been widely used in the optical fiber communication system, and are important mediators of transformation between an optical signal and an electric signal. The conventional package structure of optical transceiver component, as shown in FIG. 1 and FIG. 2, general comprises an optical transceiver which includes a transmitting optical subassembly 200 (TOSA) for transmitting an optical signal and a receiving optical subassembly 300 (ROSA) for receiving an optical signal.
In the package structure, both of the transmitting optical subassembly 200 and the receiving optical subassembly 300 contain a metal base, and a laser diode (LD)/photo diode (PD) mounted on the metal base through a sub-mount, and there are two pins provided and passed through the metal base beside the laser diode/photo diode, and the laser diode/photo diode is electrically connected to the pins via wire 400 by a wire bonding process.
The sub-mount generally consists of a passive component on which top and bottom sides are covered with a conductive layer. One side of the passive component contacts with the bottom surface of the laser diode/photo diode, and the other side contacts with the top surface of the metal base. In the sequent wire bonding process, the laser diode/photo diode is connected to the pins via the wire 400 directly or through the sub-mount so that the laser diode/photo diode is electronically connected to the circuit layout on the circuit board to transmit the electric signal.
Regarding the traditional package structure, since the height of the sub-mounts is not uniform, the top surfaces of the laser diodes and the photo diodes are not same level upon mounting on the submount, which results in the bonding wires 400 in different lengths. If the wire 400 is too long, it would cause a high inductance value which in turn yield a simultaneously switching noise disturbing the circuit function. Accordingly, there remains a need of an effective way to solve the above problem.